1. Field of the Invention
The present invention relates to a reusable support frame designed to serve as a floor for pouring concrete slabs that will be supported by vertical support beams in order to form a bridge or similar structure.
2. Description of the Related Art
Currently, the most common construction method employed when building a bridge for a roadway is to form up the floor of the road with wooden timbers, pour the concrete slab over the timbers, then remove the timbers after the concrete has hardened sufficiently. The timbers used for this purpose are generally wood planks or plywood.
This type of framing of concrete forms is time consuming and can be dangerous to the workmen who must create and then disassemble the wooden forms. Also, this method of forming is time consuming and expensive in terms of manpower and materials since the wood planks and plywood are often damaged during disassembly of the forms and can not be reused.
The present invention addresses these problems by providing frames that are adjustable to fit different road widths, that can be easily and quickly installed, that are safe from falling once locked into place, that form a strong and uniform floor for pouring cement, and that can be easily and quickly removed without damaging the forms and without endangering the workers. Thus, these forms can be reused multiple times, making them extremely cost effective to use.
The present invention is a reusable concrete support frame that can be removably supported by horizontal supporting beams while a concrete slab roadbed is poured on top of the frame when building a bridge or other similar structure. The frame has an angle iron end member at each end of the frame which removably engages the horizontal supporting beams. One of the angle iron end members is welded to two parallel spaced apart first channel irons and the other angle iron end member is also welded to two other parallel spaced apart second channel irons. The second pair of channel irons are spaced further apart than the first pair of channel irons so that the first pair insert between the second pair.
Each of first pair of channel irons has a number of bolt openings extending through it can be aligned with an associated bolt opening in the corresponding one of the second pair of channel irons so that the frame can be lengthened or shortened by selecting the appropriate bolt opening to place a bolt into. A nut secures each bolt. The bolt will serve as a pivotal axis so that the first channel irons can pivot or articulate relative to the second channel irons.
One plate is welded to the top surfaces of the first channel irons, a second plate is welded to the second channel irons, and a third plate is pivotally secured to the second plate so that the third plate pivots when the first and second channel irons pivot relative to each other. Together, the three plates form a floor onto which concrete can be poured when the frame is locked in a horizontal position. The plates extending beyond their supporting first and second channel irons so that, when several plates are used sided by side, the plates of one frame are supported by one of the second channel irons of an adjacent frame.
Each of the two angle iron end members is attached to the frame so that a first leg of each of the angle irons members extends outward away from the frame and is angled slightly downward. This makes the other leg, which is oriented downward at a right angle to the first leg, angled slightly off perpendicular. This angled arrangement of the two angle iron end members causes a space at the proximal end of the first legs of the two angle iron end members and at the distal end of the second legs relative to the horizontal support beams. This space allows the frame to be removed from between the horizontal supporting beams and the concrete slab that will eventually be poured on top of the frame.
A horizontal bar is welded or otherwise permanently attached between the first channel irons at one end of the first channel irons. The horizontal bar is provided with a rod that extends outward toward the second angle iron end member. A sliding lock bar extends between the second channel irons and is movable longitudinally along the second channel irons. The sliding lock bar has two unshaped arms that slidably engage the second channel irons so the sliding lock bar is movable. The sliding lock bar includes a tab that extends upward and has a rod-receiving opening in it for removably receiving the rod on the horizontal bar. To lock the frame in a horizontal position, the sliding lock bar is moved toward the first angle iron end member until the rod enters the rod-receiving opening in the tab of the sliding lock bar. With the rod in this position, the frame can not pivot. A locking opening is provided in the rod and a cotter pin can be removably inserted into the locking opening to lock the rod within the rod-receiving opening as a safety precaution against accidental pivoting release of the frame.
The frame can be unlocked so that it pivots or articulates to remove the frame for the horizontal supporting beams and the overlying concrete slab for reuse.